There has been known an X-ray fluorescence spectrometer configured to irradiate a sample that is an object to be measured with an X-ray and detect an element contained in the sample based on output florescent X-rays. The object to be measured is not limited to a solid sample, and may be a liquid sample, that is, a sample having flowability.
For example, in Patent Literature 1, there is disclosed a sample having flowability and a measurement method. Specifically, according to the disclosure of Patent Literature 1, a sample having flowability is first filled into a recessed portion defined by a support substrate having a hole in a bottom surface and a polymer film stuck to the support substrate so as to close the hole. Then, a porous film is arranged so as to cover a surface of the filled sample.
Further, in a case in which an X-ray tube, a detector, and the like of the X-ray fluorescence spectrometer are arranged on a lower side of the sample, when a liquid sample is spilled from a measurement container during measurement, the spilled liquid sample causes a serious failure of the X-ray fluorescence spectrometer. Therefore, when the liquid sample is an object to be measured, a tube-above optics X-ray fluorescence spectrometer in which the X-ray tube, the detector, and the like are arranged on an upper side of the sample is used. For example, there has been known a method of filling a liquid sample into a container having an air bubble reservoir and analyzing the sample, in which air bubbles are prevented from being positioned on a measurement surface, through use of the tube-above optics X-ray fluorescence spectrometer.
Further, there has also been known a method of measuring a liquid sample after dropping and drying the liquid sample. For example, there has been known an X-ray fluorescence spectrometry in a state in which the liquid sample dropped onto filter paper is dried.